Air Arms AA S510 AIR LEAK

[MartinUsher4]

A question for the experts, I have an Air Arms S510 Ultra Sporter XS Regulated that sprang a leak after shooting a few rounds off.
the leak came from the hole in the cylinder where the regulator housing lines up inside.
Sourced a set of replacement seals/rings and stripped to service.
replaced the backup ring and 23x2.5 -90 rings on the firing valve body, also the two 15x2-90's on the regulator having been directed to do so.
reassembled and tried filling, when getting to 50 or so bar the leak slowly came back again, managed to get to 100 bar and it settled down and sealed.
took a shot and the air blew out of the hole again, then settled to seal, each time shot the same result.

anyone got any ideas of why the leak blows and slows to a stop/seal, and where i should look next?
could it be the regulator not fully sealing, i am at a loss right now.
any help greatly appreciated.
regards,
Martin.

 

[nervoustrig]

Possibilities that come to mind:

1. Damaged O-ring – When the piston cycles, the O-rings break free momentarily and then have to resettle. If a small bite is taken out of one of the O-rings, it may leak for a short time until the elastomer has some time to cold flow, so to speak, and re-seal against its mating surface.
2. Hardened O-ring – Same principle as #1. This is an O-ring aging symptom so it’s not relevant if you replaced all the O-rings, but some regulators have an O-ring in an internal groove that’s easy to miss if you don’t know it’s there.
3. Scratched sealing surface - With the aid of magnification and good lighting, check the bores where each the small end and large end of the piston goes. A defect in one of these areas can produce the “leaks then seals” symptom.

[edit] On re-reading your post, the large-ish O-ring sizes you described sound like ones that seal the regulator body. The sizes for a regulator’s piston are usually smaller, and these are the ones that cause a leak from the atmospheric vent.

 

[Motorhead]

Vent hole leaks ( Regulated PCP's ) more times than not can be traced to the regulators inner "Spool" o-rings failing.
Yup Rebuild the regulator time.

 

[nervoustrig]

Just FYI the part I referred to as the piston and Scott referred to as the spool is the brass part on the left side of this picture

 

[MartinUsher4]

Thank you for the responses guys, i did replace the o-rings on the reg body as well as the firing valve body.i have not replaced the reg or seals within yet, figured it would be just as well to replace the reg itself.

i will look at the surfaces again with a scope but did not see anything foul on first inspection.

thanks
Martin.

 

[MartinUsher4]

well, all sorted now, on inspection found regulator seal to have been subjected to smearing through possible air friction/heat combo.
purchased new reg and dropped in, all good and working, not sure if its worth repairing the old one as a spare or not.

Martin.

 

[ankisip]

I have just found the same leak.
How did you release the air cylinder........it's not hand tight on O rings.
Is the thread glued? need heat?

 

[Trucker3573]

You need to rebuild the whole regulator. Every seal.

 

[ankisip]

Thanks trucker,

it needed heat to get the cylinder loose.
there is a tiny burr inside the tube vent close to the breach. it chewed the O ring when I unscrewed the tube.

I replaced all of the O rings, but noticed the O ring that seals the Reg Housing into the breach had been damaged on factory fitment.
The Reg Housing was extremely difficult to slot into the breach. Silicone grease everywhere.

Has anyone replaced the NBR90 with NBR70, with success?
NBR70 seem to work in other pcp In my experience. (Weihrauch, Daystate, RTI P3).

Refitting the tube to the breach, the burr chewed the O ring, as previous.
I can’t fix the burr.

The tube leaked from the same vent hole.
For Whatever Reason there are bleed holes everywhere in this section of the action. An engineering nightmare compared to the likes of my Weihrauch 100s.

For such a nice and accurate rifle this section needs to be seriously redesigned.
ankisip

 

[ankisip]

Thanks trucker,

it needed heat to get the cylinder loose.
there is a tiny burr inside the tube vent close to the breach. it chewed the O ring when I unscrewed the tube.

I replaced all of the O rings, but noticed the O ring that seals the Reg Housing into the breach had been damaged on factory fitment.
The Reg Housing was extremely difficult to slot into the breach. Silicone grease everywhere.

Has anyone replaced the NBR90 with NBR70, with success?
NBR70 seem to work in other pcp In my experience. (Weihrauch, Daystate, RTI P3).

Refitting the tube to the breach, the burr chewed the O ring, as previous.
I can’t fix the burr.

The tube leaked from the same vent hole.
For Whatever Reason there are bleed holes everywhere in this section of the action. An engineering nightmare compared to the likes of my Weihrauch 100s.

For such a nice and accurate rifle this section needs to be seriously redesigned.
ankisipView attachment 585646

 

[MartinUsher4]

unlike ankisip i found the internals very well polished and deburred, no sharp edges anywhere, high standard of manufacturing practices evident, a business i am all to familiar with myself as a partner in a large machine shop.
removing the theaded block from the cylinder is easy enough using a strap wrench with a rubber strip to protect the machined and blued finishes.
all O-rings for the rifle i purchased locally for $18.00 CAD local though had to purchase 4 sets to make it worthwhile for supplier, isn't mark up wonderful.
cleaned thoroughly before re-assembly and all went back together easily, cocked and charged no problem.
i would recommend looking for local seal specialists for replacements rather than O.E.M.
just my opinion, i'm still waiting for Airgun Supply and Air Arms to let me know when they will have stock again, i think they have forgotten....
Martin.

 

[ankisip]

Did you use NBR70, instead of 90?
The Regulator housing is sealed inside the cylinder air space, and I question the need for NBR90 for this Oring.
Trying to punch the housing into the breach may be why the Oring got damaged...... in factory fitment, and also when I used silicone grease to get them together.
The softer 70 might provide a seal and not get damaged.

With the burr; the Reg Vent hole is punched, and therefore the inside needs to be linished smooth.
This was most likely done, but..... I'll take pics of the damaged Oring for AA.

The rifle was fine for the two weeks that I have had it. Took a few sighting shots on 5 @ 40m, then some on 1 @ 8m with Hades .22. Nice ragged hole , 5ft/lbs and 350ft/sec.....perfect for inside pesting in sheds. Came home topped it up and lost air overnight.
Just need it sorted.

 

[MartinUsher4]

Did you use NBR70, instead of 90?
The Regulator housing is sealed inside the cylinder air space, and I question the need for NBR90 for this Oring.
Trying to punch the housing into the breach may be why the Oring got damaged...... in factory fitment, and also when I used silicone grease to get them together.
The softer 70 might provide a seal and not get damaged.

With the burr; the Reg Vent hole is punched, and therefore the inside needs to be linished smooth.
This was most likely done, but..... I'll take pics of the damaged Oring for AA.

The rifle was fine for the two weeks that I have had it. Took a few sighting shots on 5 @ 40m, then some on 1 @ 8m with Hades .22. Nice ragged hole , 5ft/lbs and 350ft/sec.....perfect for inside pesting in sheds. Came home topped it up and lost air overnight.
Just need it sorted.

I sourced factory part numbers and durometer of O-rings, rifle is high pressure don't screw with it.
take a look at post #6 where I show the regulator and it's smeared rings, pressure bypassed and vented, whether it was factory or just use failure I wont know, again, replaced as factory part numbers to match durometer, greased and reassembled, no issues to date, the regulator is and easy out and in, the clip I used was bent to use in 4 hole plug wrench flat end of reg.
hope this helps.

 

[ankisip]

I hear you Martin.

 

[ankisip]

Why I query the Oring composition, RTI Arms has 3 Orings at NBR90, the rest NBR70.
300bar bottle, up to 180bar past the Reg.
It’s all to do with the groove/squish design.

Just a question in case there has been further advice in this regard.

First string testing he rifle on the 5 powers.
For a low powered rifle the flexibility is excellent for pesting both in and outside buildings.
Using JSB Jumbo Heavy .22.
Comparing the figures against HW100S at 7ft/lb, and HW100T at 27ft/lb, it gives me greater options for pellets and distances. It also shoots NSA 17.5gr slugs very well.
When I get it sorted I’ll be able to get some more tests done.
S510XS Ultimate Sporter .22

 

[ankisip]

 

[ankisip]

 

[terrykuz]

What is the warranty on these late model AA510s? This seems to me a manufacturing issue.

 

[ankisip]

Correct Terry.
So far, the reply from AA is;
"Try fixing it yourself, sorry for the inconvenience".
Lifetime in UK; 3 weeks in Australia.

The least they can do is send me a set of Orings, in the case that I can satisfactorily remove the burr.
Consumer laws are relatively strong here, so normally, the minimum would be New Cylinder and Orings from the manufacturer through Australian supplier.
Nice rifle, Not happy.

 

[BSJ]

When I installed DIY regs in my AA rifles I used a hone to deburr the vent hole.
Like this. https://www.amazon.com/gp/aw/d/B0009OR8WU?psc=1&ref=ppx_pop_mob_b_asin_title